Subject: Re: Further scheduler changes
To: None <>
From: Christos Zoulas <>
List: tech-kern
Date: 09/20/2006 19:12:08
In article <>,
Thor Lancelot Simon  <> wrote:
>On Tue, Sep 19, 2006 at 06:14:59PM +0100, David Laight wrote:
>> On Tue, Sep 19, 2006 at 01:30:56AM +0200, Daniel Sieger wrote:
>> > Hi all,
>> > ok, I would like to get some suggestions about how to further improve
>> > the scheduler. The first thing that comes to my mind is to design a
>> > general scheduling API that allows for the implementation of different
>> > algorithms and/or models. FreeBSD did a similar job, IIRC. So, the
>> > next steps would be i) to define the API itself and ii) to separate
>> > the traditional 4.4BSD scheduler from kern_synch.c.
>> > 
>> > Any comments/suggestions?
>> One 'really useful feature' that any change should allow for is
>> process affinities (ie tying a process to a physical cpu).
>I should note that we have already been offered a patch to do this, by
>Christian Limpach.  It was rejected -- to my utter disbelief -- by an
>influential developer because, since it packed "which run queue am I
>on" into an integer with one bit per CPU, it would require later revision
>to accomodate systems with more than 32 processors.
>I think this is a canonical example of how the best is the enemy of the
>good.  ;-)  But perhaps when I get a 32-chip system, I will feel otherwise.

What is the PR of the patch?